Setting 580 EXII ETTL for 40D
I want to set the 580 so that it will provide fill flash in AV or TV mode without dictating a predefined shutter speed.
So I cycled through the Mode button, but it doesnt display ETTL, just TTL or M or Multi.
So I looked around the web, and I found this for configuring the settings from the 40 D: http://www.youtube.com/watch?v=fUIE7LZ_rcg Cool!
But when I select Flash Control->External Flash Func Setting, it says, "This menu cannot be displayed. Incompatible flash or flash's power is turned off." Not cool.
Any help on how I can do this, in the 40D or in the 580, please?